This invention relates to barrel reclaimers for bulk materials, and in particular to the drums of such reclaimers.
Known barrel reclaimers comprise an elongate cylindrical drum rotatably mounted at its opposite ends on support frames which run on rails at the sides of a bulk material stockpile. Openings in the drum have scoop buckets projecting from them to pick up material from the stockpile as the drum is rotated and progressed along the rails into the stockpile. The material picked up by the buckets is deposited on a conveyor which extends axially through the interior of the drum and which delivers the material to a fixed conveyor at the side of the reclaimer track for further transport.
Because it is supported only at its ends, the drum of a barrel reclaimer is subject to beam loading and as it rotates the structure of the drum is therefore subjected to cyclic fluctuating loads. Despite the precautions that have been taken in the design of such equipment the problem remains that barrel reclaimer drums are prone to fatigue cracking after a relatively short operating life, in particular because of the higher local stresses occurring at the bucket openings. Despite taking such known measures such as the rounding of the corners of the openings, this problem remains a critical feature of the design of barrel reclaimer drums and there has been no satisfactory solution to it.